Patents by Inventor Mengchu Cai
Mengchu Cai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20150199449Abstract: A system and method is provided for query processing comprises: creating an index of a database and ordering a set of index candidates from the index into a list based on a set of heuristic rules. A query defining a query path is then reduced into a list of single path expressions. Each index candidate is matched against the list of single path expressions according to the ordering of the index candidates. The matched candidate nodes are also verified to insure that they satisfy the query path.Type: ApplicationFiled: January 26, 2015Publication date: July 16, 2015Inventors: Mengchu Cai, Ruiping Li, Guogen Zhang
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Publication number: 20150074134Abstract: System, method, and computer program product to modify a received query, the received query including a first predicate specifying a comparison operator and a second predicate specifying an IS NULL operator, by replacing the comparison operator of the first predicate with an extended comparison operator, and removing the IS NULL operator from the received query, the extended comparison operator configured to support searching of NULL values in a database management system (DBMS), wherein the extended comparison operator is configured to return rows having column data matching a value predefined to represent NULL values.Type: ApplicationFiled: September 10, 2013Publication date: March 12, 2015Inventors: Thomas A. Beavin, Mengchu Cai, Dengfeng Gao, Jae H. Lee, Li-Mey Lee, Terence P. Purcell, Shengxi Suo
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Publication number: 20150074135Abstract: System, method, and computer program product to modify a received query, the received query including a first predicate specifying a comparison operator and a second predicate specifying an IS NULL operator, by replacing the comparison operator of the first predicate with an extended comparison operator, and removing the IS NULL operator from the received query, the extended comparison operator configured to support searching of NULL values in a database management system (DBMS), wherein the extended comparison operator is configured to return rows having column data matching a value predefined to represent NULL values.Type: ApplicationFiled: June 25, 2014Publication date: March 12, 2015Inventors: Thomas A. BEAVIN, Mengchu CAI, Dengfeng GAO, Jae H. LEE, Li-Mey LEE, Terence P. PURCELL, Shengxi SUO
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Patent number: 8972377Abstract: A system and method is provided for query processing comprises: creating an index of a database and ordering a set of index candidates from the index into a list based on a set of heuristic rules. A query defining a query path is then reduced into a list of single path expressions. Each index candidate is matched against the list of single path expressions according to the ordering of the index candidates. The matched candidate nodes are also verified to insure that they satisfy the query path.Type: GrantFiled: October 25, 2007Date of Patent: March 3, 2015Assignee: International Business Machines CorporationInventors: Guogen Zhang, Ruiping Li, Mengchu Cai
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Patent number: 8903814Abstract: Techniques are described for processing a query to produce query results, the query specifying at least a first timestamp value. Embodiments receive the query for processing and access a database index containing a plurality of database keys. The database index contains one or more database index keys, each of which includes at least a timestamp value and a time zone value. Embodiments compare the first timestamp value specified in the query with a portion of one the database index keys to locate at least a portion of the query results. More specifically, the compared portion of the database index key excludes the time zone value. The located portion of the query results is then retrieved.Type: GrantFiled: July 7, 2011Date of Patent: December 2, 2014Assignee: International Business Machines CorporationInventors: Mengchu Cai, Yao Ching Stephen Chen, Ruiping Li, Wei Li, Robert William Lyle
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Patent number: 8666969Abstract: Various aspects of this disclosure are directed to receiving, by a computing device, a first table join query that may include a first group of table identifiers that identify the two or more tables. The computing device may determine whether the first table join query includes an outer join command. When the first table join query includes the outer join command, the computing device may compare the first group of table identifiers and a second group of table identifiers of one or more pre-joined tables to determine whether each of the first table identifiers matches at least one of the second group of table identifiers. The computing device may further determine whether a predicate associated with each table identifier matches a predicate associated with a matching second table identifier. When each of the predicates match, the computing device may rewrite the first table join query.Type: GrantFiled: November 14, 2011Date of Patent: March 4, 2014Assignee: International Business Machines CorporationInventors: Thomas A. Beavin, Mengchu Cai, Ruiping Li, James A. Ruddy
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Patent number: 8495085Abstract: Methods and apparatus, including computer program products, implementing and using techniques for performing a partial update of a hierarchically structured document referencing one or more records stored in a database. An expression specifying one or more updates to be applied to the document is received. The document is searched to find update target position(s). Based on the received expression, a pending update list is built. When an update target position is found, a row of a document column in a base table is updated with the new version number for the document. New database records for insertion into the new document version are generated from the pending update list. Old database records to be replaced are identified. A database table for the document is updated to mark the old database records as obsolete and to add new database records to be referenced in the new version of the document.Type: GrantFiled: September 27, 2010Date of Patent: July 23, 2013Assignee: International Business Machines CorporationInventors: Mengchu Cai, Yu Chen, Eric Naoto Katayama
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Publication number: 20130124500Abstract: Various aspects of this disclosure are directed to receiving, by a computing device, a first table join query that may include a first group of table identifiers that identify the two or more tables. The computing device may determine whether the first table join query includes an outer join command. When the first table join query includes the outer join command, the computing device may compare the first group of table identifiers and a second group of table identifiers of one or more pre-joined tables to determine whether each of the first table identifiers matches at least one of the second group of table identifiers. The computing device may further determine whether a predicate associated with each table identifier matches a predicate associated with a matching second table identifier. When each of the predicates match, the computing device may rewrite the first table join query.Type: ApplicationFiled: November 14, 2011Publication date: May 16, 2013Applicant: International Business Machines CorporationInventors: Thomas A. Beavin, Mengchu Cai, Ruiping Li, James A. Ruddy
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Publication number: 20130013617Abstract: Techniques are described for processing a query to produce query results, the query specifying at least a first timestamp value. Embodiments receive the query for processing and access a database index containing a plurality of database keys. The database index contains one or more database index keys, each of which includes at least a timestamp value and a time zone value. Embodiments compare the first timestamp value specified in the query with a portion of one the database index keys to locate at least a portion of the query results. More specifically, the compared portion of the database index key excludes the time zone value. The located portion of the query results is then retrieved.Type: ApplicationFiled: July 7, 2011Publication date: January 10, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Mengchu Cai, Stephen Yao Ching Chen, Ruiping Li, Wei Li, Robert W. Lyle
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Publication number: 20120078942Abstract: Methods and apparatus, including computer program products, implementing and using techniques for performing a partial update of a hierarchically structured document referencing one or more records stored in a database. An expression specifying one or more updates to be applied to the document is received. The document is searched to find update target position(s). Based on the received expression, a pending update list is built. When an update target position is found, a row of a document column in a base table is updated with the new version number for the document. New database records for insertion into the new document version are generated from the pending update list. Old database records to be replaced are identified. A database table for the document is updated to mark the old database records as obsolete and to add new database records to be referenced in the new version of the document.Type: ApplicationFiled: September 27, 2010Publication date: March 29, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Mengchu Cai, Yu Chen, Eric Naoto Katayama
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Multi-Versioning Mechanism for Update of Hierarchically Structured Documents Based on Record Storage
Publication number: 20110302195Abstract: A method for multi-versioning data of a hierarchically structured document stored in data records includes: changing document data in one or more data records, each data record assigned a record identifier, the data record including a plurality of nodes assigned a node identifier, and the document assigned a document identifier; storing an update timestamp in a base table row referencing the document identifier; storing in each changed data record a start timestamp for a start of a validity period for the changed data record and an end timestamp for an end of the validity period; and storing the start timestamp and the end timestamp in one or more node identifier index entries referencing the document identifier, the record identifier, and the node identifier. A version of the document may be obtained using node identifier index entries satisfying a version timestamp.Type: ApplicationFiled: June 8, 2010Publication date: December 8, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Mengchu Cai, Eric N. Katayama, Guogen Zhang, Shirley Zhou -
Patent number: 7840552Abstract: Techniques are provided that determine that a query includes at least one subquery that may be correlated or decorrelated. An internal representation of the query that represents the subquery in both correlated and decorrelated form is generated, wherein the internal representation includes at least one virtual table.Type: GrantFiled: April 16, 2008Date of Patent: November 23, 2010Assignee: International Business Machines CorporationInventors: Thomas Abel Beavin, Mengchu Cai, Yao-Ching Stephen Chen, Hsiuying Yen Cheng, Fen-Ling Lin, Irene Ching-Hua Liu, Jerry Mukai, Demai Ni, Yoichi Tsuji, Li Xia, Ying Zeng
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Patent number: 7657570Abstract: Disclosed is method for processing an aggregate function. Rows that contain a reference to intermediate result structures are grouped to form groups. For each group, aggregate element structures are formed from the intermediate result structures and, if the aggregate function specifies ordering, the aggregate element structures are sorted based on a sort key.Type: GrantFiled: April 20, 2007Date of Patent: February 2, 2010Assignee: International Business Machines CorporationInventors: Yun Wang, Fen-Ling Lin, Yao-Ching Chen, Mengchu Cai, Jason Alexander Cu, Allan Benjamin Lebovitz, Li-Mey Lee, Guogen Zhang
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Publication number: 20090112858Abstract: A system and method is provided for query processing comprises: creating an index of a database and ordering a set of index candidates from the index into a list based on a set of heuristic rules. A query defining a query path is then reduced into a list of single path expressions. Each index candidate is matched against the list of single path expressions according to the ordering of the index candidates. The matched candidate nodes are also verified to insure that they satisfy the query path.Type: ApplicationFiled: October 25, 2007Publication date: April 30, 2009Applicant: International Business Machines CorporationInventors: Guogen Zhang, Ruiping Li, Mengchu Cai
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Publication number: 20080222176Abstract: A method and system for evaluating a path query are disclosed. The path query corresponds to a query tree including a plurality of query nodes. At least one query node corresponds to at least one predicate and is at a level. The predicate(s) are evaluated for previous query node(s). The method and system include scanning data nodes of a document and determining if the data nodes match the query nodes. The method and system also include placing data related to the data node in match stacks corresponding to matched query nodes. The data for the query node(s) include attribute(s) corresponding to the predicate(s). The method and system further include propagating a matching of the at least one query node backward to a matching of the at least one previous query node.Type: ApplicationFiled: May 19, 2008Publication date: September 11, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Mengchu CAI, Jason Alexander Cu, Fen-Ling Lin, Guogen Zhang, Qinghua Zou
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Publication number: 20080215534Abstract: Techniques are provided that determine that a query includes at least one subquery that may be correlated or decorrelated. An internal representation of the query that represents the subquery in both correlated and decorrelated form is generated, wherein the internal representation includes at least one virtual table.Type: ApplicationFiled: April 16, 2008Publication date: September 4, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Thomas Abel BEAVIN, Mengchu CAI, Yao-Ching Stephen CHEN, Hsiuying Yen CHENG, Fen-Ling LIN, Irene Ching-Hua LIU, Jerry MUKAI, Demai NI, Yoichi TSUJI, Li XIA, Ying ZENG
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Patent number: 7376646Abstract: Techniques are provided that determine that a query includes at least one subquery that may be correlated or decorrelated. An internal representation of the query that represents the subquery in both correlated and decorrelated form is generated, wherein the internal representation includes at least one virtual table.Type: GrantFiled: June 17, 2005Date of Patent: May 20, 2008Assignee: International Business Machines CorporationInventors: Thomas Abel Beavin, Mengchu Cai, Yao-Ching Stephen Chen, Hsiuying Yen Cheng, Fen-Ling Lin, Irene Ching-Hua Liu, Jerry Mukai, Demai Ni, Yoichi Tsuji, Li Xia, Ying Zeng
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Publication number: 20070198479Abstract: A method and system for evaluating a path query are disclosed. The path query corresponds to a query tree including a plurality of query nodes. At least one query node corresponds to at least one predicate and is at a level. The predicate(s) are evaluated for previous query node(s). The method and system include scanning data nodes of a document and determining if the data nodes match the query nodes. The method and system also include placing data related to the data node in match stacks corresponding to matched query nodes. The data for the query node(s) include attribute(s) corresponding to the predicate(s). The method and system further include propagating a matching of the at least one query node backward to a matching of the at least one previous query node.Type: ApplicationFiled: February 16, 2006Publication date: August 23, 2007Applicant: International Business Machines CorporationInventors: Mengchu Cai, Jason Cu, Fen-Ling Lin, Guogen Zhang, Qinghua Zou
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Publication number: 20070192285Abstract: Disclosed is method for processing an aggregate function. Rows that contain a reference to intermediate result structures are grouped to form groups. For each group, aggregate element structures are formed from the intermediate result structures and, if the aggregate function specifies ordering, the aggregate element structures are sorted based on a sort key.Type: ApplicationFiled: April 20, 2007Publication date: August 16, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Yun WANG, Fen-Ling LIN, Yao Ching CHEN, Mengchu CAI, Jason CU, Allan LEBOVITZ, Li-Mey LEE, Guogen ZHANG
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Patent number: 7243098Abstract: Disclosed is a method, system, and program for processing an aggregate function. Rows that contain a reference to intermediate result structures are grouped to form groups. For each group, aggregate element structures are formed from the intermediate result structures and, if the aggregate function specifies ordering, the aggregate element structures are sorted based on a sort key.Type: GrantFiled: December 19, 2002Date of Patent: July 10, 2007Assignee: International Business Machines CorporationInventors: Yun Wang, Fen-Ling Lin, Yao Ching Stephen Chen, Mengchu Cai, Jason Alexander Cu, Allan Benjamin Lebovitz, Li-Mey Lee, Guogen Zhang